Malicious PDF — malware analysis report

Static analysis result for SHA-256 536d052d49c853fe…

MALICIOUS

PDF

82.9 KB Created: 2021-08-20 00:49:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: effb47ad9778763e9e5254c483e1ddbb SHA-1: 51006689481fae183fd76bf3390c5180a510b35b SHA-256: 536d052d49c853fe28a295024d4ab737afa96df9fe57235721ea42075dec6db8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting. The presence of embedded URLs and the nature of the heuristics suggest a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://infrive.ru/uplcv?utm_term=formal+business+proposal+letter+sample PDF link annotation
    • http://laibros.com/ckeditor/userfiles/files/xigudajazijer.pdfIn PDF document text
    • http://kolesnikov.pro/ckfinder/userfiles/files/vujutapunuforeb.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/15735635ee38defbb8a1449406795b60/64759243151.pdfIn PDF document text
    • http://moon-villa123.com/CKEdit/upload/files/79174462589.pdfIn PDF document text
    • http://www.chp.pl/ckfinder/userfiles/files/37808919252.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/7cdb216acd061758d7b57378206145ef/nazuwipozo.pdfIn PDF document text
    • http://alessandrobelleseveterinario.eu/userfiles/files/musoko.pdfIn PDF document text
    • http://classicalgardenfountains.com/uplds/file/13140327302.pdfIn PDF document text
    • http://dztechfin.com/upload/file///43478206234.pdfIn PDF document text
    • http://31kouqiang.com/userfiles/file/1626191545.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/e60fef83accb8a9e73e0a1db054b0cdf/kogezuxexazexujorabikogi.pdfIn PDF document text
    • http://high-keenltd.com/userfiles/file/292371506.pdfIn PDF document text
    • http://murielbellhomes.com/userfiles/files/84647173351.pdfIn PDF document text
    • https://chrmglobal.com/userfiles/file/87872289234.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/epf2vrmdctsup8ga61ruhm1h1e/xutotanovipipivu.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088470e02512---10519107516.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608194f532f56---naxajezekebebibabonoguri.pdfIn PDF document text
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc84347dd5---zedudipatagetosarinivib.pdfIn PDF document text
    • http://sklepjola.pl/userfiles/file/tafumivifipazagafilogup.pdfIn PDF document text
    • http://sedaciesupravy.sk/media/file/kimelemovoxekiwezokovikil.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/pjo16vc87rq1to6lkdhbu8ao1v/rejozupizarumokamuwepat.pdfIn PDF document text
    • https://www.vpn-solutions.com.pe/ckfinder/userfiles/files/nobajemutagerorug.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f05a8f2c97---vetamivar.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/temudovezijuzaxuwiju.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160872633dc797---lotovale.pdfIn PDF document text
    • https://skatrip.com/basefile/skatripcom/files/71626094336.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF30 17980 bytes
SHA-256: eb6d25e5caec1d8ccd919bc1b768ad3c4c2ec826e11b994da8e6a2de257d0430
font_01_sfnt_off00010d53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D53 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001256a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1256A 10632 bytes
SHA-256: 3fc346c5cdccc5ec737018787f7df80033fe97df7ad4badadda80e3489948d84